Electrostatically Driven Polarization Flop and Strain-Induced Curvature in Free-Standing Ferroelectric Superlattices

Yaqi Li*, Edoardo Zatterin, Michele Conroy, Anastasiia Pylypets, Fedir Borodavka, Alexander Björling, Dirk J. Groenendijk, Edouard Lesne, Andrea D. Caviglia, More Authors

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

1 Citation (Scopus)
6 Downloads (Pure)

Abstract

The combination of strain and electrostatic engineering in epitaxial heterostructures of ferroelectric oxides offers many possibilities for inducing new phases, complex polar topologies, and enhanced electrical properties. However, the dominant effect of substrate clamping can also limit the electromechanical response and often leaves electrostatics to play a secondary role. Releasing the mechanical constraint imposed by the substrate can not only dramatically alter the balance between elastic and electrostatic forces, enabling them to compete on par with each other, but also activates new mechanical degrees of freedom, such as the macroscopic curvature of the heterostructure. In this work, an electrostatically driven transition from a predominantly out-of-plane polarized to an in-plane polarized state is observed when a PbTiO3/SrTiO3 superlattice with a SrRuO3 bottom electrode is released from its substrate. In turn, this polarization rotation modifies the lattice parameter mismatch between the superlattice and the thin SrRuO3 layer, causing the heterostructure to curl up into microtubes. Through a combination of synchrotron-based scanning X-ray diffraction imaging, Raman scattering, piezoresponse force microscopy, and scanning transmission electron microscopy, the crystalline structure and domain patterns of the curved superlattices are investigated, revealing a strong anisotropy in the domain structure and a complex mechanism for strain accommodation.

Original languageEnglish
Article number2106826
Pages (from-to)12
JournalAdvanced Materials
Volume34
Issue number15
DOIs
Publication statusPublished - 2022

Keywords

  • ferroelectric domains
  • free-standing membranes
  • microtubes
  • strain engineering

Fingerprint

Dive into the research topics of 'Electrostatically Driven Polarization Flop and Strain-Induced Curvature in Free-Standing Ferroelectric Superlattices'. Together they form a unique fingerprint.

Cite this